Multipole circuit breaker



Oct. 26, 1954 L,- W, COLE 2,692,926

MULTIPOLE CIRCUIT BREAKER Original Filed Sept. 21, 1950 2 Sheets-Sheet lF1E Z *L r w INVENTOR. /56 OU/5 W. COLE A54 m By mm ,312 E 1 ik @L Oct.26, 1954 w COLE 2,692,926

MULTIPOLE CIRCUIT BREAKER Original Filed Sept. 21, 1950 2 Sheets-Sheet 2El -5 Fg-7 A JNVENTOR. OU/5 W. CO/.

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TTORNE YS Patented Oct. 26, 1954 MULTIPOLE CIRCUIT BREAKER Louis W.Cole, New York, N. Y., assignor to Federal Electric Products Company,Newark, N.

a corporation of Delaware Continuation of application Serial No.186,013,

September 21, 1950. This application September 6, 1952, Serial No. 308

22 claims. 1

The present invention relates to multi-pole circuit breakers and totripping devices therefor. More particularly, the invention is concernedwith a multi-pole circuit breaker which can be manually opened andclosed and which is also opened automatically at all of the poles uponthe occurrence of an overload in the circuit at any one of the poles.

The primary object of the present invention is the provision of amulti-pole circuit breaker formed of a plurality of single pole circuitbreakers of standard construction and provided with a tripping device ofnovel construction for tripping all of the poles thereof upon theoccurrence of an overload or other abnormal condition in the circuit ofone of the poles thereof.

The above and other objects, features and advantages of the presentinvention will be more fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. l is a side view of a multi-pole circuit breaker according to thepresent invention;

Fig. 2 is an end view of the circuit breaker as seen from the line 2 2of Fig. 1;

Fig. 3 is a top View of the circuit breaker;

Fig. 4 is a view similar to Fig. l with the cover removed showing thecircuit breaker in the closed condition thereof;

Fig. 5 is a partial sectional view taken on the line 5-5 of Fig. 4;

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 4;

Fig. 7 is a partial sectional View taken on the line 1 7 of Fig. 4;

Fig. 8 is a partial sectional view taken on the line 8-8 of Fig. 4; and

Fig. 9 is a fragmentary view similar to Fig. 4 showing the circuitbreaker in the tripped condition thereof.

Referring now to the drawings in detail., the multi-pole circuit breakerI0 of the present invention is here shown as comprising the companionsingle-pole circuit breakers I 2, I4 and I6. The circuit breakermechanism for each of said single pole circuit breakers is containedWithin a casing or housing I8 formed by a body part 20 and a cover orclosure part 22 therefor. Each of said parts is formed, preferably by amolding operation, from a suitable insulating material such as, forexample, Bakelite The housing parts are secured together in any suitablemanner, such as by means of the screws 24 and the nuts 25.

Contained within each housing I8 is a. stationary contact 25 carried bya terminal member 28, and a movable contact member 3l! provided with acontact 32 engagcable and disengageable with said stationary contact.Said movable contact member is mounted for pivotal movement in amanually operable member, here shown as the insulated handle 34. Agenerally U-shaped actuating member 3G is mounted at one end thereof,for pivotal movement on the pivot pin 38, a spring 39 being connectedbetween said movable member 3B and said member 36 to form a togglearrangement therewith7 as is hereinafter described in detail, saidactuating member and spring constituting an operating mechanism for themovable contact member. At its free end said actuator 3B is providedwith a. portion 31 in normally latched engagement with a iiexable latchmember 40, preferably formed of spring metal and provided at one endthereof with a part 42. Said member 40, at the other end thereof, isbodily carried by and is secured in any suitable manner to a thermostatelement 44, here shown as a exible bi-metallic strip. Latch member 40and element 44 together constitute a trip device, as hereinafterdescribed. Said member 44 is electrically connected to the movableContact member 3U by the flexible conductor 45, one end of saidbi-metallic strip being mounted on the terminal member 43 and the freeend thereof abutting said part 42.

Pursuant to the present invention, provision is made for tripping all ofthe poles of the circuit breaker l il upon the tripping of any one polethereof. In this connection, it will be understood that upon the passageof a predetermined current through the thermostat 44, said thermostatwill flex in the direction of the arrow A in Fig. 4 to move part 42 insaid direction. Said movement will carry the exible member 46 in thedirection of the arrow for unlatching the latter from member 36. Uponsaid unlatching, the actuator 36, under the tension of theaforementioned toggle, which is overcentered, as illustrated in Fig. 4,pivots in a clockwise direction, viewing Fig. 4, to reverse the togglewhereupon the movable contact member 30 is pivoted in acounter-clockwise direction for disengaging contact 32 from Contact 2S,the circuit breaker mechanism assuming the tripped position illustratedin Fig. 9.

In order to provide for the tripping of all of the poles of the circuitbreaker i0 upon the tripping of one of the poles thereof, there isprovided, for each pole of the circuit breaker i9, a

tripping element 563. As here shown, the tripping element 5i) ispreferably formed of a suitable insulating material and comprises agenerally cylindrical body portion 52 (Fig. 8) which is mounted forrotation in the casing i8. Referring now specifically to the casing ofthe single pole circuit breaker i2, it will be seen that the cover 22thereof is provided with a bearing recess 5d (Fig. 6) for the end 55 ofthe tripping element 5t. The companion casing part 2t is provided with abearing aperture 58 in registry with said bearing recess 54, and the endSii of the tripping element extends through said aperture. It will benoted that the end 56 is provided with a slotted portion t2 and that theend et is provided with an axially extending portion E34, the purpose ofwhich is hereinafter described. The tripping element 5d is alsoprovided, adjacent the end 56 thereof.l with an integral upwardlyextending portion 56 provided with the cam forming marginal edge Bt andwith the dependent intermediate :linger portion 1E).

As illustrated in Fig. 4, in the circuit closed condition of the circuitbreaker the tripping element is in set position wherein the fingerportion l@ is inclined forwardly of the axis of body portion 52 to abutthe lower end of the flexible latch member 4c, and the upwardlyextending portion $6 is inclined rearwardly of said axis. Theaforementioned pivotally mounted actuator 35 is provided with alaterally oifset portion 12 (Figs. 6 and 8) in engagement with the camsurface portion 68 of said portion te. Upon the tripping of one of thecircuit breaker mechanisms, as previously described, the actuator 35 ispivoted in a -clockwise direction from the retracted latched dispositionthereof and the portion 'l2 thereof moves downwardly along the camsurface 68 to rotate the tripping element 5t in a counterclockwisedirection from its set position, viewing Fig. 4, whereupon the dependingportion 10 is rotated in a direction forwardly and upwardly from its setposition. As illustrated in Fig. 6, the individual tripping element 55in each of the circuit breakers l2, lll, and I6, respectively, arejoined for unitary operation and together comprise the tripping member5I. More specifically, it will be noted that the extending portion 64 ofthe tripping element in circuit breaker i2 extends into the casing ofcircuit breaker Il-l and is positioned in the slot 62 of the trippingelement 5i) in said circuit breaker i4, It will be noted that saidcircuit breaker I4 is provided with aligned apertures 'M and 16 in thecover and body portions, respectively thereof, the slotted portion 6?.of its tripping element extending into aperture M and the end portion 60thereof extending through said bearing aperture 16 into the bearingaperture 18 provided in the cover of circuit breaker I5, the extendingportion 64 of the latter portion @d being positioned in the slot 62 ofthe tripping element 5!) in the circuit breaker l5. The other end ofsaid latter tripping element is mounted for rotation in the bearingrecess 8l) provided in the body portion of circuit breaker I 6 inregistry with the bearing aperture 'i8 thereof. From the above, it willbe apparent that all three tripping elements 5t are mounted for conjointand simultaneous rotation, together constituting said tripping member5i.

Upon the tripping of any one pole of the circuit breaker lc upon theoccurrence of a predetermined current in the circuit of said pole, theportion 65 of the companion tripping element 5i! is rotated rearwardlyof the position illustrated in Fig. 4 by portion l2 of the companionactuator 36 whereby to rotate said tripping member 5l in acounter-clockwise direction. As a result of said rotation, the portion1l), in the untripped circuit breakers, move from the positionillustrated in Fig. l to the position illustrated in Fig. 9 whereby tomove the companion latch members 150 to said latter position fordisengaging said latch members from the companion latching portions 3lfor actuating the toggles of said untripped circuit breakers,respectively, to disengage the companion movable contacts from thestationary contacts thereof.

It will be noted that, in said tripped condition, the portions 'i2 ofmembers 345 prevent the companion tripping devices E@ from rotating in aclockwise direction, the portions 66 thereof being in abutment withraised detent portions 82, respectively, of the casings. It will also benoted that the depending portions Iii have moved the companion flexiblemembers 4t sufciently to disengage the respective parts i2 from thecompanion thermostat element All.

1n order to reset the circuit breaker li), after the tripping thereof,the handle 34 in each casing it is rotated in a clockwise direction,from the position illustrated in Fig. 9, whereupon a depending portionS- thereof, which abuts a laterally extending pin 86 provided inactuator 35, moves said pin for pivoting the actuator in acounter-clockwise direction about its pivot 38. until the latchingportion 3l reengages the latch member dil. It will be noted that saidlatch member is provided with a latch part 87, which cooperates withsaid portion 31 to latch the actuator. Upon said rotation of member 35,the part if thereof releases the portion 65 of the tripping element 5dwhich is freed for rotation in a clockwise direction, viewing Fig. 9,the flexible member iii pressing against the depending portion 'l0 toeffect said rotation. Since all of the handles are mounted for conjointmovement, as described below, all of the tripping elements are returnedsimultaneously to the position thereof illustrated in Fig. 4. Thehandles are then moved to the position illustrated in Fig. 4. toreengage the movable contacts and the stationary contacts, ashereinafter described.

Referring now to the individual circuit breaker mechanisms in greaterdetail, it will be noted that each handle 34 is provided with the pivotportions 953 (Fig. 5) mounted in the aligned bearing recesses 92provided in the companion casing, said handle extending through theopening el@ provided therefor in said casing. The handle 3d is providedwith the aforementioned spaced depending portions 34, each provided witha bearing portion 95 (Fig. 9) and being spaced thereabove as at et (Fig.5). The movable contact member 3i) is provided with the bifurcations B8which are mounted for pivotal movement in said portions 95,respectively, the free ends liiii of said bifurcations abutting the apexIt! (Fig. 9) formed in said bearing portions 95, respectively, wherebythe member 3i! is mounted for pivotal movement in said handle. The bightm2 of the U-shaped actuator 3e extends into the space 96 between thehandle portions 3ft, the previously mentioned coil spring 39 having oneend thereof secured in the movable contact member as at Hifi, the otherend thereof being secured in said portion m2 as at illi. It will benoted that said spring is disposed for movement between the portions 98of the movable contact member and forms a toggle therewith, said springends constituting the outer centers of said toggle and the ends |00 ofthe movable contact member constituting the intermediate center of saidtoggle. As illustrated in Fig. 4, the toggle is over-centered in theclosed condition of the circuit breaker in a direction for biasing theactuator 36 for clockwise rotation, said toggle also biasing the movablecontact member 36 into rm engagement with the stationary contact 2B.Upon the previously described movement of flexible latch member 40 formoving latch portion 8l thereof out of engagement with the actuator, thetoggle is effective to rotate the actuator in a clockwise directionwhereupon the toggle center, constituted by the end |06 of spring 39secured in said actuator, is carried beyond the intermediate togglecenter and the latter is thereupon carried into the position illustratedin Fig. 9 for overcentering the toggle in the opposite direction, with asnap action, for disengaging the contact 32 from the contact 26.

Provision is made for commencing the disengagement of said contactsbefore said snap action of the toggle. In this connection, there isprovided a pivoted cam member |08 which is pivotally mounted on a pinIIl secured in the casing. Member |68 is provided with an interiorgroove I |2 having the groove portion I |4 and the groove portion ||6laterally offset therefrom. In addition, said member |08 is providedwith the depending portion I |8. Member 36 is provided, adjacent thepivoted end thereof, with the shouldered pin (Fig. '7), the free end |22thereof extending into groove portion IIS in the circuit closedcondition, as in Fig. 4. Upon the tripping of the circuit breakermechanism and the resultant clockwise rotation of actuator 85, aspreviously described, end portion |22 is carried thereby out of grooveportion I I 6 and into groove portion II4 for pivotally moving member|08, in a counter-clockwise direction, the depending portion I8 thereofbeing moved against the movable contact member 3U and moving the latterout of engagement with the contact 26 before the collapse of the toggle,as previously described.

The thermal current responsive member 44 is operable not only inresponse to the heating effect of the current passing therethrough, butis operable also under the control of electro-magnetic means foreffecting disengagement of the latch member 4D carried thereby from theactuator member 36, and the arrangement is preferably such that, as hereshown, the electro-magnetic means is energized by the current whichpasses through the thermal current responsive member 44. For thispurpose, an electro-magnetic member |24 is mounted on member 44 near thefree end thereof and a companion armature |26 is mounted on the flexiblemember 4D being disposed in spaced confronting relation toelectro-magnetic member |24. It will be noted that upon the occurrenceof an overload in excess of that for which the circuit breaker isdesigned to open under the control of the thermal member 44, by theflexing of the latter in response to lthe heating thereof whereby tocarry latch member 40 out of engagement with actuator 36, theelectro-magnetic device is operable instantaneously to effectdisengagement of portion 81 of member 46 from latching portion 3l. Itwill be understood that upon the occurrence of such excess overload, themagnetic attraction between members |24 and |26 results in thedeflection of latch member 46 for disengaging the latter from thecompanion portion 3l of member 36, and in this connection it will beunderstood that since member 40 is flexible to a much greater extentthan member 44 which carries member |24, member |26 is movable bymagnetic attraction toward member |24, thus deecting or unlatchingmember 40 from the companion member 3.

To provide for simultaneously resetting of all the poles of the circuitbreaker I0, the handles 34 thereof are interconnected by the channelbridging member |28. Upon the tripping of the circuit breaker III, thebridging member |28 and the handles 34 thereof assume the positionindicated in Fig. 9. By moving the bridging member forwardly thereof,the previously described depending portions 84 move the aforementionedpins 86 for rotating the members 36 from the position illustrated inFig. 9 to the position illustrated in Fig. 4 wherein they are inengagement with the companion flexible members 40, as previouslydescribed. The bridging member |28 is then moved rearwardly to theposition indicated in Fig. 4 for oversetting the toggle mechanisms andfor engaging the movable contacts 32 withthe stationary contacts 26,respectively.

As here shown, the circuit breakers are mounted in laterally disposedrelation upon the insulated mounting plate |30. Said plate is providedat the opposing ends thereof with the aligned hook elements |32, theelements at one end of the mounting plate being in registry with thecompanion elements |32, respectively, at the other end thereof. Eachhooked element is removably secured to the plate by a screw |34. Thehousing I8 of each of the circuit breakers is provided, at each endthereof, with a recessed portion |36, respectively, for receiving ahooked element |32 for releasably mounting the circuit breakers on plateI 36.

This application is a continuation of my abandoned application, SerialNumber 186,013 filed September 21, 1950.

While I have shown and described the preferred embodiment of myinvention, it will be understood that various changes may be made in thepresent invention without departing from the underlying idea orprinciples of the invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

l. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit and atripping element associated with said mechanism, said circuit breakermechanism comprising a movable conta ct member, an operating mechanismtherefor an il a trip device operable to latch said operating mechanismin circuit-closed condition and to unlatch the same for operating saidmovable member to circuitopen condition upon said occurrence, saidtripping element being mounted independently of said operating mechanismand trip device, said element having means operable upon the tripping ofits associated circuit-breaker mechanism to operate the tripping elementat another pole to trip the circuit breaker mechanism thereof, and saidtripping element at said other pole having means operable upon thetripping of its associated circuit breaker mechanism to trip the circuitbreaker mechanism of said rst mentioned element, each of said trippingelements being disposed for operation by the operating mechanism of itsassociated circuit breaker mechanism, re-

spectively, when said associated operating mechanism, respectively, isunlatched from the trip device thereof whereby to effect the operationof said other tripping element.

2. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit and atripping element associated with said mechanism, said circuit breakermechanism comprising a movable contact member, an operating mechanismtherefor and a trip device operable to latch said operating mechanism incircuit-closed condition and to unlatch the same for operating saidmovable member to circuitopen condition upon said occurrence, saidtripping element being mounted independently of said operating mechanismand trip device, said element having means operable upon the tripping ofits associated circuit-breaker mechanism to operate the trippingelements at the other poles to trip the circuit breaker mechanismsassociated therewith, respectively, and said 1latter tripping elementseach having means operable, upon the tripping of the circuit-breakermechanism associated therewi h, respectively, to operate the trippingelements at the other poles, to trip the circuit breaker mechanisms ofsaid other poles, each of said tripping elements being disposed in thepath of movement of its associated operating mechanism for movementthereby when said associated operating mechanism is unlatched from thetrip device thereof whereby to effect the oper-v ation of said othertripping elements.

3. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit and atripping element associated with said mechanism, said circuit breakermechanism comprising a movable contact member, an operating mechanismtherefor and a trip device operable to latch sais` operating mechanismin circuit-closed condition and to unlatch the same for operating saidmovable member to circuit-open condition upon said occurence, saidtripping element being mounted independently of said operating mechanismand trip device, said element having means operable upon the tripping ofits associated circuit breaker mechanism to operate the trippingelements at the other poles to trip the circuit breaker mechanismsassociated therewith, respectively, and said latter tripping elementseach having means operable, upon the tripping of the circuit breakermechanism associated therewith, respectively, to operate the trippingelements at the other poles, to trip the circuit breaker mechanisms ofsaid other poles, each of said tripping elements being disposed foroperation by th-e operating mechanism of its associated circuit breakermechanism when said associated operating mechanism is unlatched from thetrip device thereof whereby to effect the operation of said othertripping elements, and said means being rotary means extending betweensaid poles and provided with said tripping elements each injuxtaposition to its associated operating mechanism.

4. In a multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit, saidcircuit breaker mechanism comprising a movable contact member, actuatingmeansv therefor and a trip device operable to latch said actuating meansin circuit-closed condition and to unlatch the same for operating saidmovable member to circuit-open condition upon said occurrence; thecombination with said actuating means and trip device of a trippingelement disposed in the path of movement of said actuating means foroperation thereby upon the unlatching thereof, said tripping elementhaving means to operate a similar element in a circuit breaker at acompanion pole to trip the circuit-breaker mechanism of the latter inresponse to the tripping of circuit breaker mechanism associated withsaid first mentioned element.

5. In a multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit, saidcircuit breaker mechanism comprising a movable contact member, anoperating mechanism therefor and a trip device operable to latch saidoperating mechanism in circuit-closed condition and to unlatch the samefor operating said movable member to circuitopen condition upon saidoccurrence; the combination with said operating mechanism and tripdevice of a tripping element mounted independently thereof and disposedin the path of movement of the operating mechanism for operation therebyupon the unlatching thereof, said tripping element having means tooperate a similar element in a circuit breaker at a companion pole totrip the circuit-breaker mechanism of the latter in response to thetripping of circuit breaker mechanism associated with said iirstmentioned element, said tripping element being provided with angularlyrelated parts, one of said parts being engaged by said operatingmechanism to rotate said tripping element, and the other of said partsengaging said trip device for moving the latter in a direction tounlatch said operating mechanism.

6. In a multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit, saidcircuit breaker mechanism comprising a movable contact member, anoperating mechanism therefor and a trip device operable to latch saidoperating mechanism in circuit-closed condition and to unlatch the samefor operating said movable member to circuit-open condition upon saidoccurrence; the combination with said operating mechanism and tripdevice of a tripping element mounted independently thereof and disposedin the path of movement of the operating mechanism for operation therebyupon the unlatching thereof, said tripping element having means tooperate a similar element in a circuit breaker at a companion pole totrip the circuitbreaker mechanism of the latter in response to thetripping of circuit breaker mechanism associated with said firstmentioned element, said tripping element having provision for thereleasable securement thereof to said similar element for effecting saidoperation of the latter.

7. A single-pole circuit breaker adapted for use with a similar circuitbreaker to constitute a multi-pole circuit breaker, each of saidsinglepole circuit breakers being a self-contained independentlyoperable unit provided with a circuit-breaker mechanism independentlytrippable upon the occurrence of predetermined current in the circuitthereof, said circuit-breaker mechanism comprising a movable contactmember, an operating mechanism therefor and a trip device operable tolatch said operating mechanism in circuit-closed condition and tounlatch the same for operating said movable member to circuitopencondition upon said occurrence, said singlepole circuit breaker beingprovided with a tripping element mounted therein independently of theoperating mechanism and trip device thereof, said element having meansto operate a similar element in the companion circuit breaker to tripthe circuit-breaker mechanism of the latter in response to the trippingof the circuit breaker mechanism associated with said first mentionedelement, and said means providing for operation of its associatedtripping element by said similar element, upon the tripping of thecircuit-breaker mechanism of the latter, to trip the circuitbreakermechanism of said single-pole circuit breaker.

8. A single-pole circuit breaker adapted for use with a similar circuitbreaker to constitute a multi-pole circuit breaker, each of saidsinglepole circuit breakers being a self-contained independentlyoperable unit provided with a circuitbreaker mechanism independentlytrippable upon the occurrence of predetermined current in the circuitthereof, said circuit-breaker mechanism comprising a movable contactmember, an operating mechanism therefor and a trip device operable tolatch said operating mechanism in circuitclosed condition and to unlatchthe same for operating said movable member to circuit-open conditionupon said occurrence, said single-pole circuit breaker being providedwith a tripping element mounted therein independently of the operatingmechanism and trip device thereof, said element having means toreleasably unite said element with a similar element in the othersingle-pole circuit breaker for operatingr said similar element to tripthe circuit-breaker mechanism of the latter in response to the trippingof the circuit breaker mechanism associated with said first mentionedelement, and said means providing for operation of its associatedtripping element by said similar element, upon the tripping of thecircuit-breaker mechanism of the latter, to trip the circuit-breakermechanism of said singlepole circuit breaker.

9. A multi-pole circuit breaker comprising at least a pair ofsingle-pole circuit breakers each of which is a self-containedindependently operable unit provided with a circuit-breaker mechanismindependently trippable upon the occurrence of predetermined current inthe circuit thereof, said circuit-breaker mechanism comprising a movablecontact member, an operating mechanism therefor and a trip deviceoperable to latch said operating mechanism in circuit-closed conditionand to unlatch the same for operating said movable member tocircuit-open condition upon said occurrence, each of said units beingprovided with a tripping element mounted therein independently of theoperating mechanism and trip device thereof, said element having meansoperable, upon the tripping of the circuit-breaker mechanism thereof, tooperate the tripping element in the companion unit to trip thecircuit-breaker mechanism of the latter, and said tripping element ofthe companion unit having means operable, upon the tripping of thecircuit breaker mechanism of the latter, to operate said first mentionedelement to trip the circuit breaker mechanism thereof.

10. A multi-pole circuit-breaker comprising a plurality ofself-contained and independently operable single-pole circuit-breakerunits, each unit being provided with a circuit-breaker mechanism whichcomprises a movable contact member, an operating mechanism therefor anda trip device operable to latch said operating mechanism incircuit-closed condition and to unlatch the same for operating saidmovable member to circuitopen condition upon the occurrence ofpredetermined current in the circuit thereof, and a tripping elementprovided in each unit and mounted therein independently of the operatingmechanism and trip device thereof, said tripping element having meansoperable in response to the tripping of its circuit-breaker mechanism tooperate the tripping elements in the companion units to trip thecircuit-breaker mechanisms of the latter, and said latter trippingelements each having means operable, upon the tripping of its associatedcircuit breaker mechanism, to operate the tripping elements of the otherunits to trip the associated circuit breaker mechanism, respectively,thereof.

11. A single-pole circuit breaker adapted for use with a similar circuitbreaker to constitute a multi-pole circuit breaker, each of saidsinglepole circuit breakers being a self-contained independentlyoperable unit provided with a circuitbreaker mechanism independentlytrippable upon the occurrence of predetermined current in the circuitthereof, said circuit-breaker mechanism comprising a movable contactmember, an operating mechanism therefor and a trip device operable tolatch said operating mechanism in circuit-closed condition and tounlatch the same for operating said movable member to circuit-opencondition upon said occurrence, said single-pole circuit breaker beingprovided with a tripping element mounted therein independently of theoperating mechanism and trip device thereof, said element having meansto operate a similar element in the companion circuit breaker to tripthe circuit-breaker mechanism of the latter in response to the trippingof the circuit breaker mechanism associated with said rst mentionedelement, and said means providing for operation of its associatedtripping element by said similar element, upon the tripping of thecircuit-breaker mechanism of the latter, to trip the circuitbreakermechanism of said single-pole circuit breaker, said tripping elementbeing disposed in the path of movement of said operating mechanism formovement thereby when said operating mechanism is unlatched from thetrip device thereof to effect said operation of said similar element.

12. A multi-pole circuit breaker comprising at least a pair ofsingle-pole circuit breakers each of Which is a self-containedindependently operable unit provided With a circuit-breaker mechanismindependently trippable upon the occurrence of predetermined current inthe circuit thereof, said circuit-breaker mechanism comprising a movablecontact member, an operating mechanism therefor and a trip deviceoperable to latch said operating mechanism in circuit-closed conditionand to unlatch the same for operating said movable member tocircuit-open condition upon said occurrence, each of said units beingprovided with a tripping element mounted therein independently of theoperating mechanism and trip device thereof, said element having meansoperable, upon the tripping of the circuit-breaker mechanism thereof, tooperate the tripping element in the companion unit to trip thecircuitbreaker mechanism of the latter, and said tripping element of thecompanion unit having means aeeaeae operable, upon the tripping of thecircuit breaker mechanism of the latter, to operate said first mentionedelement to trip the circuit breaker mechanism thereof, said trippingelements being releasably united and being mounted for rotation in theirrespective units, each element having angularly related portions one ofwhich is disposed in the path of movement of the operating mechanism ofits unit for movement thereby when said operating mechanism is unlatchedby its trip device, the other portion abutting its trip device formoving the latter in a direction to unlatch its operating mechanism,whereby, upon the tripping of one of said circuit-breaker mechanisms,the tripping element thereof will be rotated by the operating mechanismthereof and rotate the tripping element in the other unit so that saidother portion in the other unit will effect the unlatching of theoperating mechanism thereof.

13. A single-pole circuit breaker adapted for use with a similar circuitbreaker to constitute a multi-pole circuit breaker, each of said singlepole circuit breakers being a self-contained independently operable unitprovided with a circuit-breaker mechanism independently trippable uponthe occurrence of predetermined current in the circuit thereof, saidcircuit-breaker mechanism comprising a movable contact member, anoperating mechanism therefor and a trip device operable to latch saidoperating mechanism in circuit-closed condition and to unlatch the samefor operating said movable member to circuit-open condition upon saidoccurrence,

said single-pole circuit breaker being provided with a tripping elementmounted therein independently of the operating mechanism and trip devicethereof, said element having means to operate a similar element in thecompanion circuit breaker to trip the circuit-breaker mechanism of thelatter in response to the tripping of the circuit breaker mechanismassociated with said first mentioned element, and said means providingfor operation of its associated tripping element by said similarelement, upon the tripping of the circuit breaker mechanism of thelatter, to trip the circuit breaker mechanism of said single-polecircuit breaker, said tripping element being disposed in the path ofmovement of said operating mechanism for movement thereby when saidoperating mechanism is unlatched from the trip device thereof to efiectsaid operation of said similar element, said operating mechanism havinga laterally extending part in engagement with said tripping element toeffect the movement thereof.

1li. 1n a single-pole circuit breaker adapted for use with a similarcircuit breaker to constitute a multi-pole circuit breaker, each of saidsingle-pole circuit breakers being a self-contained independentlyoperable unit provided with a circuit-breaker mechanism independentlytrippable upon the occurrence of predetermined current in the circuitthereof, and said circuitbreaker mechanism comprising a movable contactmember, an operating mechanism therefor and a trip device operable tolatch said operating mechanism in circuit-closed condition and tounlatch the same for operating said movable member to circuit-opencondition upon said occurrence; the combination with said operatingmechanism and trip device of a tripping element mounted independentlythereof and disposed in the path of movement of the operating mechanismfor operation thereby upon the un- 12 latching thereof, said trippingelement having means to operate a similar element in the companioncircuit breaker to trip the circuit-breaker mechanism of the latter inresponse to the tripping of the circuit breaker mechanism associatedwith said first mentioned element.

15. In a single-pole circuit breaker adapted for use With a similarcircuit breaker to constitute a multi-pole circuit breaker, each of saidsingle-pole circuit breakers being a self-contained independentlyoperable unit provided with a circuit-breaker mechanism independentlytrippable upon the occurrence of predetermined current in the circuitthereof, and said circuitbreaker mechanism comprising a movable contactmember, an operating mechanism therefor and a trip device operable tolatch said operating mechanism in circuit-closed condition and tounlatch the same for operating said movable member to circuit-opencondition upon said occurrence; the combination with said operatingmechanism and trip device of a tripping element mounted independentlythereof and disposed in the path of movement of the operating mechanismupon the unlatching thereof, said tripping element having means tooperate a similar element in the companion circuit breaker to trip thecircuit-breaker mechanism of the latter in response to the tripping ofthe circuit breaker mechanism associated with said first mentionedelement, said tripping element being provided with angularly relatedparts, one of said parts being engaged by said operating mechanism torotate said tripping element, and the other of said parts engaging saidtrip device for moving the latter in a direction to unlatch saidoperating mechanism.

16. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit, eachof said mechanisms comprising a movable contact member, an actuatormeans operatively connected to said movable contact member and alatching means for latching its associated actuator means incircuitclosed disposition thereof and for releasing the same foroperating said movable member to circuit-open condition upon saidoccurrence, and means operatively common to all poles of said circuitbreaker and disposed for operation by a released actuator means uponsaid occurrence in the associated circuit of said released actuatormeans for operating the circuit-breaker mechanism at a companion pole tothe circuitopen condition thereof.

17. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit, eachof said mechanisms comprising a movable contact member, an actuatormeans operatively connected to said movable contact member anda latchingmeans for latching its associated actuator means in circuitcloseddisposition thereof and for releasing the same for operating saidmovable member to circuit-open condition upon said occurrence, saidactuator means including a pivotally mounted member releasablyrestrained by said latching means from movement to circuit-opendisposition thereof, and means extending between the poles of saidcircuit breaker, said latter means being disposed in the path ofmovement of the pivotally mounted member at each pole for op- 13 erationby a released member upon said occurrence in the associated circuit foroperating the circuit breaker mechanism at a companion pole to thecircuit-open condition thereof.

18. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon the occurrence ofpredetermined current in the circuit thereof to open said circuit, eachof said mechanisms comprising a movable contact member, an actuatormeans operatively connected to said movable contact member and alatching means for latching its associated actuator means incircuitclosed disposition thereof and for releasing the same foroperating said movable member to circuit-open condition upon saidoccurrence, said actuator means including a pivotally mounted memberreleasably restrained by said latching means from movement tocircuit-open disposition thereof, and means extending between the polesof said circuit breaker, said latter means being disposed in the path ofmovement of the pivotally mounted member at each pole for operation by areleased member upon said occurrence in the associated circuit foroperating the circuit breaker mechanism at a companion pole to thecircuit-open condition thereof, said latter means being mounted forrotation and said pivotally mounted member having a predeterminedportion engageable with said latter means to effect said rotationthereof.

19. In a multi-pole automatic circuit breaker, a plurality of pairs ofseparable contacts, releasably restrained circuit breaker mechanismindividual to each pair of contacts to eifect separation of thecorresponding pair of contacts upon release thereof, independentlyoperable latching means for each of said plurality of mechanisms, acurrent responsive control means for each pair of contacts, eachlatching means being operable by its associated control means inresponse to predetermined current through its associated pair ofcontacts to release its associated mechanism, and means disposed foroperation by a released mechanism and operatively common to all poles ofthe breaker for causing unlatching of the latching means for all otherpoles in response to operation of the latching means in one pole by saidcontrol means of said one pole.

20. In a multi-pole automatic circuit breaker, a plurality of pairs ofseparable contacts, releasably restrained circuit breaker mechanismindividual to each pair of contacts to effect separation of thecorresponding pair of contacts upon release thereof, independentlyoperable latching means for each of said plurality of mechanisms, acurrent responsive control means for each pair of contacts, eachlatching means being operable by its associated control means inresponse to predetermined current through its associated pair ofcontacts to release its associated mechanism, and means mounted foroperation independently of the individual latching means and operativelycommon to all poles of the breaker for causing unlatching of thelatching means for all other poles in response to lil) operation of thelatching means in one pole by said control means of said one pole.

21. In a multi-pole circuit breaker having at each pole thereof astationary contact, an operating means, a movable contact member pivotedon said operating means to engage and to disengage the stationarycontact for closing and opening the circuit, respectively, an actuatormember mounted for movement between circuitclosed and circuit-openpositions, respectively, thereof, and an overcentering springinterconnected between said members for effecting opening and closingmovements of said movable contact member; means for latching saidactuators in the circuit-closed condition thereof, a current responsivecontrol means at each pole operable in response to a predeterminedcurrent in the circuit of its associated pole to release one of saidactuators for movement to its circuit open position whereby toovercenter the spring associated with the released actuator for open--ing the circuit at the pole of the released actuator, and means foreffecting the movement of each other actuator to the circuit-openposition thereof in response to said movement of the released actuator,whereby to overcentei' the spring associated with said other actuatorfor opening the circuit at the pole thereof.

22. In a multi-pole circuit breaker having at each pole thereof astationary contact, an operating means, a movable contact member pivotedon said operating means to engage and to disengage the stationarycontact for closing and opening the circuit, respectively, an actuatormember mounted for movement between circuitclosed and circuit-openpositions, respectively, thereof, and an overcentering springinterconnected between said members for effecting opening and closingmovements of said movable contact member; means for latching actuatorsin the circuit-closed condition thereof, a current responsive controlmeans fixedly supported at each pole operable in response to apredetermined current in the circuit of its associated pole to releaseone of said actuators for movement to its circuit-open position wherebyto overcenter the spring associated with the released actuator foropening the circuit at the pole of the released actuator, and means foreffecting the movement of each other actuator to the circuit-openposition thereof in response to said movement of the released actuator,whereby to overcenter the spring associated with said other actuator foropening the circuit at the pole thereof, said last mentioned means beingcommon to said poles and extending therebetween.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 2,343,612 Frank et al Mar. '7, 1944 2,362,850 Platz Nov. 14,1944 2,551,397 Rowe May l, 1951 2,551,822 Bingenheimer May 8, 1951

